How pure is your fish oil?

April 12, 2016

Are you taking fish oil? Naturopath and medical herbalist Paul Keogh explains why it’s important to make sure you choose a fish oil supplement that’s made to the most stringent purity standards.

View PDF


First published by Go Vita in Go Magazine Issue 41

Over the past 40 years, an enormous body of scientific research has been published confirming the benefits of the omega-3s found in fish oil for the heart, blood vessels, joints, brain, eyes and more.

Here are just a few of the many reasons the omega-3s are considered so important to human health:

Cardiovascular support: In healthy people, the omega-3s work to protect heart and blood vessel health in numerous ways, including helping to maintain cholesterol, triglycerides and blood pressure within the normal range. They also have supportive effects on healthy blood coagulation, the normal rhythm of the heart, the integrity of the capillaries, and help healthy people regulate their blood sugar.

Joint health: If you’re suffering from mild arthritis or stiff, swollen or aching joints, taking a fish oil supplement may help by relieving pain and inflammation, reducing swelling and improving joint mobility.

Brain and eye function: Omega-3s are required for the normal functioning of the brain and eyes, and help to support healthy vision, moods and cognitive functioning (mental processing). Omega-3s are considered especially important for eye health as we get older, and for brain development and cognitive function in babies and children.

Why take a fish oil supplement?

With such strong evidence to validate the importance of these essential fatty acids, you’d expect that most health conscious people would make sure to eat the 2-3 servings of oily fish each week recommended by health authorities.

But in reality, only around two in five Australians do eat fish that frequently, leaving the other 60 per cent of us likely to be consuming suboptimal levels of omega-3 from our diets.

So it’s little wonder that omega-3s are one of the most popular nutritional supplements in Australia, taken by around a third of those over the age of 45, predominantly as fish oil.

Worried about the fishy aftertaste?

However, if you don’t take fish oil supplements because you don’t like the fishy aftertaste or embarrassing fish scented burps, you’re not alone!

A recent survey has revealed that almost a quarter of Australians don’t take fish oil supplements due to concerns about taste and odour, suggesting that while they’re aware of the health benefits of the omega-3s, many are simply not prepared to put up with these unpleasant issues.

Supplement manufacturers can reduce the likelihood that your supplement will leave you with a fishy aftertaste or unpleasant burping by adding natural flavourings to the oil itself and the capsule that surrounds it.

Taking your fish oil supplement in an enteric-coated capsule that won’t break down until it reaches the small intestine (where the essential fatty acids are absorbed) also helps minimise these issues.

Fundamentally though, if the taste or smell of your fish oil supplement puts you off taking it, it’s possible that its contents have degraded in some way. This occurs because the chemical structure of the omega-3 fatty acids found in fish oils makes them highly susceptible to oxidation (a form of free radical damage) during processing and storage.

When oxidation occurs, the levels of desirable components such as the omega- 3s EPA and DHA in the oil decline, and the levels of undesirable compounds such as peroxides increase, bringing with them a stronger fishy odour and reducing the palatability of the oil.

To reduce the potential for oxidation having negative effects on the smell of your supplement and – more importantly – reducing its therapeutic benefits, Australian quality guidelines require manufacturers to set limits for the maximum permissible levels of key oxidation markers in fish oil supplements.

In fact, some manufacturers hold their products to even higher standards than those required by the Australian guidelines, as illustrated by the graph below, which demonstrates the difference in oxidation markers allowed under the quality guidelines and those used in the production of VivoMega™ TG90, a highly concentrated, premium quality fish oil.


These high levels of purity are obtained by concentrating the fish oil used in VivoMega™ TG90 until at least 90 per cent of it is comprised of triglycerides, and a far lower proportion is comprised of the other compounds found in non-concentrated oils. This creates a raw material with a more uniform chemical structure, ultimately resulting in a supplement that stays fresher and tastes better.

Oxidation can be further reduced by the inclusion of a natural antioxidant in the fish oil supplement. The naturally occurring carotenoid astaxanthin is a good choice, as it demonstrates highly potent antioxidant activity, estimated as being approximately more than 100 times more active in the body than those of vitamin E.

But what about mercury?

By now you’re probably aware that although fish are a wonderful source of omega-3 fatty acids, the heavily polluted state of the world’s oceans means that some species (especially those at the top of the food chain, like sharks, marlin and swordfish) are also a source of mercury and other heavy metals, along with industrial pollutants such as dioxins, furans and polychlorinated biphenyls (PCBs).

The good news is that while you can never know the levels of mercury and other contaminants that are present in the fish in your diet, Australian fish oil supplements are required to be thoroughly tested to ensure that they don’t add to the toxic load on your body.

Again, some manufacturers set even more stringent purity standards than those stipulated by Australian health authorities.

For example, the graph below shows the maximum permissible levels of heavy metals and other contaminants under the Australian quality guidelines, and compares them with those used in the manufacture of VivoMega™ TG90.


VivoMega™ TG90 is produced from fish species such as anchovies, sardines and chub mackerel. These small fish are lower down the food chain than larger, more predatory species such as sharks and marlin, and therefore accumulate lower levels of pollutants in their oil and flesh prior to being harvested. In addition, their short life cycles and the low levels of demand for them for culinary consumption make them a sustainable source of fish oil for use in supplements.

Paul Keogh is the executive and technical director for Global Therapeutics P/L trading as Fusion Health. Paul is a qualified naturopath and medical herbalist with 25 years combined experience in clinical practice and the development of integrated Chinese and western herbal medicines.

Comments are closed.

Women's Health Book